Biodegradable ferroelectric molecular crystal with large piezoelectric response

Abstract

Transient implantable piezoelectric materials are desirable for biosensing, drug delivery, tissue regeneration, and antimicrobial and tumor therapy. For use in the human body, they must show flexibility, biocompatibility, and biodegradability. These requirements are challenging for conventional inorganic piezoelectric oxides and piezoelectric polymers. We discovered high piezoelectricity in a molecular crystal HOCH 2 (CF 2 ) 3 CH 2 OH [2,2,3,3,4,4-hexafluoropentane-1,5-diol (HFPD)] with a large piezoelectric coefficient d 33 of ~138 picocoulombs per newton and piezoelectric voltage constant g 33 of ~2450 × 10 −3 volt-meters per newton under no poling conditions, which also exhibits good biocompatibility toward biological cells and desirable biodegradation and biosafety in physiological environments. HFPD can be composite with polyvinyl alcohol to form flexible piezoelectric films with a d 33 of 34.3 picocoulombs per newton. Our material demonstrates the ability for molecular crystals to have attractive piezoelectric properties and should be of interest for applications in transient implantable electromechanical devices.

Computational analysis of electrical stimulation to promote tissue healing for hernia repair at varying mesh placement planes

“…24 The unique properties of this new material allow for an increased voltage output compared to PVDF, and can have a wide variety of uses in tissue regeneration. 24 There are a wide variety of electroactive materials that have been shown to increase cell proliferation, migration, and reduce bacterial load that could be incorporated with current synthetic hernia repair meshes to improve healing and reduce recurrence rates. 22 Additionally, the abdominal tissue layers naturally have some local strain due to muscle contractions or mechanical loading, but the low-level electrical stimulation should not induce harmful local strains.…”

“…22,23 Polymeric polyvinylidene difluoride (PVDF), a piezoelectric material, is widely used for flexible electronic devices due to its light weight, flexible nature, as well as low toxicity. 24 PVDF could be incorporated with current synthetic meshes to become an electrically active composite mesh. 25 A recent study by Zhang et al discovered a highly biocompatible, high flexibility, no cytotoxicity piezoelectric molecular crystal, HOCH 2 (CF 2 ) 3 CH 2 OH [2,2,3,3,4,4-hexafluoropentane-1,5, diol] (HFPD) that is also biodegradable in a film form.…”

“…25 A recent study by Zhang et al discovered a highly biocompatible, high flexibility, no cytotoxicity piezoelectric molecular crystal, HOCH 2 (CF 2 ) 3 CH 2 OH [2,2,3,3,4,4-hexafluoropentane-1,5, diol] (HFPD) that is also biodegradable in a film form. 24 The unique properties of this new material allow for an increased voltage output compared to PVDF, and can have a wide variety of uses in tissue regeneration. 24 There are a wide variety of electroactive materials that have been shown to increase cell proliferation, migration, and reduce bacterial load that could be incorporated with current synthetic hernia repair meshes to improve healing and reduce recurrence rates.…”

Ferroelectrochemistry: Advancing biodegradable molecular ferroelectric towards biomedical applications

“…Combined with the Curie's principle, Neumann's principle and Landau's phenomenological theory, ferroelectrochemistry summarized and proposed the molecular design principles of ferroelectrics, namely "quasi-spherical theory", "introducing homochirality" and "H/F substitution". 3,4 To address the aforementioned issues, Zhang et al developed an organic small molecule ferroelectric material, HOCH 2 (CF 2 ) 3 CH 2 OH [2,2,3,3,4,4hexafluoropentane-1,5-diol (HFPD)], based on the H/F substitution strategy of ferroelectrochemistry and crystal engineering (Figure 1). Referring to the classical polyvinylidene fluoride (PVDF) structure, Zhang et al skillfully chose to anchor -CH 2 OH at both ends of a finite odd number of -CF 2 -groups to form an infinitely long chain-like structure by hydrogen bond interaction.…”

Temperature-tunable multiple dielectric switch in hybrid rare-earth perovskites regulated by hierarchical guest dynamics, lanthanide contraction and doping

“…Such a reconfigurable function renders them ideal candidates for use in smart stimulus-responsive system, sensing technology, and signal storage. 1–10 While mechanically activated dielectric switches, known as piezoelectrics, have played crucial roles in contemporary electrical and electronic devices, their temperature-driven counterparts are less developed but have aroused a growing interest in recent years. 11–24…”